Laser mode - laser enable pin not triggered as expected at G0/G1

[MadTooler]

Hello again. I am having fun applying grblHAL via a Pico RP2040 to a 2 axis CNC running in laser mode. Not a laser, but similar intended function where I need the "spindle" to stop upon G0 commands and start upon G1 or related commands.

I only need on/off to my spindle. I do not need PWM. I am using the spindle/laser enable pin as my only spindle output. Perhaps that is related to the issue I am seeing.

The issue... From the beginning of the gcode, all G0 commands after M3 are performed with the spindle/laser pin enabled. Is this as intended or is this an issue? Should I be using the PWM spindle pin instead and if so, can that be set to non PWM output?

Thanks!

[terjeio]

Try using M4 and set $9=3.

[MadTooler]

Thanks for the reply and suggested solution.

Try using M4 and set $9=3.

It looks like those settings may be working. I need to test it a bit more.

I could not find what the value of 3 in setting $9 is doing. Can you explain or point me to the wiki that I possibly overlooked?

Also, I have been tweaking the default values in the firmware so future builds load up proper without going through all the $ fixes. Where do I find the $9 value to adjust within the code?

Thanks again! My prototype machine is making some impressive projects so far. I hope to one day be able to share what it is doing and make it available for others as well.

[terjeio]

I could not find what the value of 3 in setting $9 is doing. Can you explain or point me to the wiki that I possibly overlooked?

The wiki is not up to date - I am not good at writing documentation... Use $$=9 to get this info from the controller:

$$=9
    0 - Enable (1)
    1 - RPM controls spindle enable signal (2)
Enable controls PWM output availability.
When `RPM controls spindle enable signal` is checked and M3 or M4 is active S0 switches it off and S > 0 switches it on.

Where do I find the $9 value to adjust within the code?

Here. But this value is ignored - to be fixed in the next commit. Note that the config.h has been refactored for the latest build - hopefully easier to find where to change setting defaults now. BTW the documentation generated from config.h might be easier to read - still not perfect but getting better?

My prototype machine is making some impressive projects so far.

Now you made me curious...

[MadTooler]

I saw the options under $$9 for 0 and 1. I did not see anything there or in the code for what it does when I send it 3 as you suggested. It seems to be working, but I do not understand why which always makes me worried it will at some point do something unexpected at usually the worst possible time. To confirm, it is correct at $9=3?

[terjeio]

To confirm, it is correct at $9=3?

Yes, for your use-case I belive it is.

The default value in config.h is used after all. The search for it did not return all results.